Hebrews 2:12; (Psalm 22:22)

saying,
“I will tell of your name to my brothers;
in the midst of the congregation I will sing your praise.”
(Hebrews 2:12 ESV)

This quote from Psalm refers to the Messiah in the psalm. Jesus is declaring that he will make know to his brothers (us) the character of God. He is with them. He is united with his disciples.